Can someone with technical knowledge and experience with supercharging M3's explain why its not dangerous to supercharge a E9x M3 engine which was designed to be only normally aspirated?

I’m sure during the design process by BMW engineers, all forms of stress and reliability test did not include circumstances where the engine was supercharged or turbo charged.So, given the additional stress and load on the engine parts, how can we safely assume the engine will be able to take on this new stress level. For arguments sake, if the engine was design to last 500,000 miles, how much reduced mileage will a supercharged engine last? 300,000 miles, or 400, 000 miles?

With most packages offering increase in performance in excess of 150hp above the stock motor, Will it not be mandatory to change the pistons to forged piston and alter compression ratios?

If we look at the way Alpina supercharges a BMW engine, or increasing boost in a turbo charged engine, it always includes high performance pistons, reinforced cyclinder heads and lower compression ratios. Even Mercedes AMG, who took their original M113 5.4 lit engine, increase the hp by almost 100hp by supercharging it. Engine internals and compression ratios were changed accordingly.

To properly increase performance of an engine via turbo or supercharging AND maintain the same durability as the stock motor, you should be replacing pistons, connecting rods, lowering compression ratio, etc.

With that said, as long as you are sensible about the level of boost, ensure the car does not detonate running a conservative air/fuel ratio, properly controlling timing, etc. and not constantly doing full top speed runs, the motor should last a long time.

How long? No one can say with any certainty as people do not test these supercharged M3 motors for durability the same way BMW does.

Speed costs money period. Pay more up front and have a long lasting, expensive built engine. Or, take your chances and pay less and you might end up having to pay more on the back end due to catastrophic engine failure.

Of course, there are those with 100% stock M3 motors that have blown up as well.

not trying to be an ass but most of the topics that are being questioned here have all been discussed previously, you just have to use the and read through the threads. unfortunately a lot of them ended up with childish/nasty arguments but if you read past all that BS you'll be able to find the information you are looking for.

also contact the companies that offer these systems!! i'm sure they will be more than happy to answer your questions.

@edu09 - since you're in miami why don't you stop by Active? you could talk about your concerns with them in person and maybe they'll even give you a test ride! i hear thats all it take to get convinced lol.

This thread is giving me second toughts about installing a S/C kit on my car, I was about to buy one kit but now I am not sure....the extra power you get with the S/C is tempting but......

Are there any reported cases in these forums of blown engines with S/C kits installed? I havent read any

There is, but I believe they were the same cause as those who are N/A.

I agree with the post above, why don't you check out AA? The people who engineer these products are your neighbor! Esp. since you aren't sure where to get an S/C kit installed and are skeptical with going FI.

Think of it like this if it didn't work and was going to be a problem then SC and turbo kit makers would not make kits for the car. On the other hand just know that it is a calculated risk, Yeah something could happen but thats the chance you have to take. Back when I first started modding cars my first car integra typeR I turbo knowing that tunning and all the safe guards something could still happen ever since then I have been modding my cars from the type R, 350z twin turbo and 335i. none of them really had any major problems but there was always a chance there. If it wont let you sleep at night then don't do it. Remember that there will be little problems along the way and that just comes from changing up stuff that has been specifically design to run a certain way. But my train of though is he if something breaks just replace it with something better.

For arguments sake, if the engine was design to last 500,000 miles, how much reduced mileage will a supercharged engine last? 300,000 miles, or 400, 000 miles?

There are way too many variables to tell. But if you planned on an engine lasting 1/2 as long, you probably wouldn't wind up disappointed.

Quote:

With most packages offering increase in performance in excess of 150hp above the stock motor, Will it not be mandatory to change the pistons to forged piston and alter compression ratios?

It isn't mandatory if you can rely on a certain amount of vigilance from the owner.

Quote:

If we look at the way Alpina supercharges a BMW engine, or increasing boost in a turbo charged engine, it always includes high performance pistons, reinforced cyclinder heads and lower compression ratios. Even Mercedes AMG, who took their original M113 5.4 lit engine, increase the hp by almost 100hp by supercharging it. Engine internals and compression ratios were changed accordingly.

There is no question that it is better to lower the compression for forced induction. And I bet every single one of those cars could run on 87 octane without immediately blowing up. That doesn't make it wrong if you're willing to sacrifice some of that margin of safety

Quote:

Originally Posted by edu09

Are there any reported cases in these forums of blown engines with S/C kits installed? I havent read any

There have been at least 5 supercharged engine failures (and at least 2 completely stock engine failures). That doesn't mean I'd expect a blown engine, but it is a contingency.

When proper hardware / software engineering and testing are done there is little risk involved in adding proper boost levels to the S65. You run into reduced safety margin and risk engine failure when software is not properly developed, you depend on a helper such as methanol or you attempt to push boost levels beyond the limit of what the motor can safely handle. If you do your research before purchasing a supercharger kit it can assist you in understanding what is involved and help you in making an educated decision.

not trying to be an ass but most of the topics that are being questioned here have all been discussed previously, you just have to use the and read through the threads. unfortunately a lot of them ended up with childish/nasty arguments but if you read past all that BS you'll be able to find the information you are looking for.

also contact the companies that offer these systems!! i'm sure they will be more than happy to answer your questions.

@edu09 - since you're in miami why don't you stop by Active? you could talk about your concerns with them in person and maybe they'll even give you a test ride! i hear thats all it take to get convinced lol.

I will pay a visit to Omar at Active to get a closer view of their kits, that most probably will erase any doubts that I have about the S/C systems

If I wanted a S/C'd car I would have bought a Mustang GT500. What makes the M3 so special is the NA powerplant. This is just my .02 and I know as everyone else there are different opinions out there. However, if you push the envelope be prepared for the consequences.

With over 300 S65B40 SC systems sold worldwide since 2008, we have not had a single engine malfunction. These engines are very strong and can easily take 7-8PSI boost, even in extreme racing conditions as long as the kit hardware/software is designed properly.

LOL - right because if you want a faster M3, you are just stupid. Exactly what is the comparable car to an M3 that goes 60-130 in around 8 secs? What if you just like BMWs? Still stupid or do you get a pass?

I'm not interested in SCing because I love the engine just the way it is, but calling someone stupid for doing it, instead of "upgrading", is simply an ignorant statement. This board is primarily made up of people that modify their cars; get over yourself.

also these are not roots type blowers were they dump on power almost all in an instant they are centrifugal supercharges that build boost slowly with rpm's. So its not an aggresive boost spike that puts a lot of stress on the conecting rods and other engine parts.

When proper hardware / software engineering and testing are done there is little risk involved in adding proper boost levels to the S65. You run into reduced safety margin and risk engine failure when software is not properly developed, you depend on a helper such as methanol or you attempt to push boost levels beyond the limit of what the motor can safely handle.

Not to nitpick too much but I will take exception to this. Let me reword...

Even with "proper" SC hardware, software and testing you will have reduced safety margins in any engine.

It all comes down to longevity. More power produces more stress on a variety of components not just engine internals. The lifetime of a stock M3 engine can be very long but supercharging will, statistically speaking, shorten the engines lifetime, both for the failure of internals and other components.

There is no practical way for any small FI company to duplicate (or even get close) to factory endurance and stress testing.

All the being said, AA does have a wonderful reputation and if I even went FI I would go with you guys and a SC kit.

In my opinion...supercharging definitely shortens the engine life. By how much? It depends on the quality of the kit, how much more you are asking over stock and the operator.

Personally, I wouldn't go FI with this engine...the last NA ///M engine ever??? I would just wait for the next turbo M3 and just get some software.

I'm not to sure about that forum member IMG did a compression and leak down test on his car prior and after installing his blower and figures were identical !
And I personally put 40k miles on my sedan with out one hiccup , these engine are very well built !